


Karasuma get's a turn with Nagisa/Everyone has sex with Nagisa

by orphan_account



Series: Nagisa Likes Teachers [2]
Category: Assassination Classroom
Genre: Anal Sex, BDSM, Blow Jobs, Bondage, Dream Sex, F/M, Freeform, Hand Jobs, Karasuma want's to know what's up, Karasuma wants to get in on the Nagisa action, M/M, Multi, Multiple Orgasms, Orgasm Denial, PWP without Porn, Punishment, School, Shiota Nagisa X Irina Jelavic, Shiota Nagisa X Karasuma Tadaomi, Shiota Nagisa X Koro-sensei, Shiota Nagisa/Karasuma, Shiota Nagisa/Koro-sensei, Shioto Nagisa/Irina Jelavic, Spanking, Thong, Underage - Freeform, Wet Dream, curious
Language: English
Status: Completed
Published: 2018-08-04
Updated: 2018-08-04
Packaged: 2019-06-21 12:20:03
Rating: Explicit
Warnings: Underage
Chapters: 2
Words: 3,276
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15557577
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: Irina accidentally let's it slip that she and Nagisa have been having sex to Karasuma. Instead of being mad, Karasuma get's curious and decides that he wants a piece of Nagisa as well....Later, Nagisa has a thrilling dream of a foursome with all his teachersChapter 1: Karasuma has sex with NagisaChapter 2: Nagisa's dream (In which he has sex with all his teachers)





	1. Karasuma has sex with Nagisa

**Author's Note:**

> Didn't think I'd actually post more smut, but here I am.

"Come in." Karasuma says when he here's the knock on the faculty door.  
"You wanted to see me, Karasuma-sensei?" Nagisa asks, carrying his bento box. Sometime after gym class Karasuma had asked Nagisa to see him in the faculty room during the lunch break. Nagisa had no clue as to why, but figured he should take his lunch with him.  
"Yes, sit down a moment while I finish up these papers then I'll see to you." Karasuma gestures to the empty chair sitting next to him and Nagisa sits down. "You can go ahead and eat your lunch while you wait."  
Nagisa obliges and sits down. He waits wondering as he eats what Karasuma wanted to talk to him about.  
"Alright, I'm done." Karasuma shuffles the papers he was grading until they're straight and turns to Nagisa. Nagisa stops eating and faces him politely.  
Karasuma looks him up and down for a moment looking almost puzzled. Nagisa tilts his head to one side curiously. "Is something wrong?"  
"I'm wondering why they like you so much." Karasuma says, giving Nagisa a hard look.  
"What?" Nagisa blinks.  
"Irina might have let it slip about what the two of you have been up to these past few months. She also was quick to admit that Koro-sensei is involved too, although I bet it's because she didn't want to be the only teacher in trouble." Karasuma explains. "And quite frankly, i'm disappointed in all of you."  
Nagisa's jaw drops. "A-am I in trouble?" He squeaks, starting to panic.  
"No." Karasuma shakes his head. "At least, you won't be if you manage to satisfy me."  
"P-pardon?" He had a feeling he knew what Karasuma was getting at.  
"You see, ever since the cat came out of the bag, I've been wondering what it is about you that Koro-sensei and Irina-san see in you. Instead of reporting them or you for your illicit behavior, I figured I'll see what the fuss is about."  
"You mean...you also want to have sex with me?" Nagisa asks, hesitantly.  
Karasuma nods. "Yes. I'm glad you caught on. Here's the catch, if you can satisfy my curiosity, then I'll turn a blind eye to your misdeeds."  
"Oh. Is that all?" A wave of relief washes over Nagisa and his heart begins to flutter with anticipation. "When do you want to have sex, Karasuma-san?" He wonders what sex with Karasuma would be like. Is he as kinky as Koro-sensei with his cosplay obsession or Irina with her BDSM?  
"How about now?" Karasuma looks at the clock. "We still got a good 40 minutes of the lunch break."  
"S-so soon?" Nagisa gasps. "But, it's the middle of the school day! Koro-sensei or Bitch-sensei could walk in-"  
"I took care of them." Karasuma assures the boy. "Koro-sensei is busy entertaining some assassins and Irina...well, Irina-san was ok with it. Her only condition was that I film it. Do you mind?"  
Nagisa isn't surprised to hear that about Irina. "I don't mind."  
Karasuma opens is laptop which is already set up and ready to film them.  
Nagisa is pleased that Irina wants to watch and can't wait to begin. "Then, shall we get started...?" He's already unbuttoning his school uniform and standing up.  
Karasuma smiles, which is rare coming from the usually stoic teacher. "I suppose so."  
"How do you want this to go?" Nagisa asks, now standing only in his underwear. He had become an expert at stripping within seconds.  
Karasuma's eyes travel to Nagisa's lower regions, and he smirks raising an eyebrow. "Really? That's what you're wearing under your pants?"  
Nagisa looks down and immediately blushes. He's wearing tight, leather thong that practically squeezes his crotch. "K-koro-sensei asked that I wear this today for our sex session after school!" Nagisa hurriedly explains. Already he can feel himself becoming aroused from Karasuma's gaze. He was starting to wonder if he had a teacher fetish.  
"Huh, so Koro-sensei likes that kind of thing," Karasuma shrugs. "Oh well, that's not my business. Go ahead and take that off, Nagisa-kun."  
Nagisa immediaetly obeys and soon he is standing nude with his hands behind his back in front of Karasuma. He has flashbacks to his first time having sex with Koro-sensei in the very same place and being nude for the first time in front of an adult. The memory makes him shiver and he bits his lip.  
Karasuma calmly stares at Nagisa, taking the sight of him in and admiring what he sees. "Irina-san wasn't kidding when she said you were big for someone that looks like a girl." He remarks, referring to Nagisa's 6-inch penis which to his amusement is already half hard. You're impatient too. Do you enjoy sex that much?"  
"Er..." Nagisa squirms in embarrassment. "I didn't think I'd like it at first...but Koro-sensei's cock just felt so good! And even though i'm always the sub Irina can do quite a lot in bed..." He's mind overflows with his favorite experiences and he shudders again.  
"Who's your favorite?" Karasuma ask, finally unbuttoning his own pants.  
Nagisa thinks for a moment, his pretty face scrunching up as he debates the pros and cons of Koro-sensei and Irina. "I-I don't think I can pick a favorite. Both of them make me feel so good..." By now, his penis is completely hard and waving in the air begging for attention from Nagisa just thinking of having sex with his teachers.  
Karasuma is still calmly sitting in his chair with his pants unbuttoned showing his white boxer briefs. Nagisa notices the bulge between his legs and licks his lips, pre-cum beginning to leak from the tip of his penis.  
"Come closer." Karasuma orders and Nagisa steps forward. Karasuma roughly grabs Nagisa's length and begins to stroke it.  
Nagisa moans with pleasure. He's glad his neglected cock is finally getting some attention.  
"You like that, Nagisa?" Karasuma cups Nagisa's balls with his other hand and begins to fondle them as he pumps Nagisa's erection.  
"Y-yes!" Nagisa replies. "Ah-! Please, I want more!"  
"Begging for more already? Impatient is an understatement with you." He moves his hand from Nagisa's balls and puts two fingers in Nagisa's ass and begins to stretch the boy's tight whole open. Nagisa's legs are shaking and sighs as Karasuma sticks all his fingers in and moves them in and out rapidly.  
"I like how you sound, Nagisa-kun." Karasuma finishes preparing the boy and continues to pump Nagisa until he orgasms.  
"Ah!" Nagisa cries as he releases into Karasuma's hand. Some of his cum shoots onto Karasuma's pants legs, but the teacher doesn't mind.  
"You ready for my cock now?" Karasuma asks, reaching into his boxers and pulling out his hard penis. Nagisa stares at in amazement and his penis immediately shoots up into the air once again. Karasuma is completely hung! Even more so then Koro-sensei's or Yoshida's, one the male classmates that raped him a week ago. It's practically beautiful to Nagisa eyes as it's perfectly long and thick.  
"Yes!" Nagisa nods happily, his penis and asshole twitching. "Please put it in!"  
"Then come sit in my lap." Karasuma pats his knee. Nagisa turns around and scoots into Karasuma's huge lap. Without warning, Karasuma flips Nagisa so he is lying across his lap on his stomach. "Before we begin, I still have to punish you for being a naughty student."  
"Eek!" Nagisa squeals, wiggling his butt. "Please don't!"  
"It's either this or I report you." Karasuma runs a finger teasing along Nagisa's back. "How many spanks can you handle? Twenty?"  
"I-I can do twenty." Nagisa confesses.  
"Alright. Then count along as I go. And don't you dare cum without my say-so. If you do, I'll fuck you so hard Koro-sensei will come running to see what's up. Understand?" Karasuma warns.  
"Y-yes."  
Karasuma slaps Nagisa's ass and the boy yelps in alarm. "Yes, sir." Karasuma corrects him.  
"Yes, sir!" Nagisa's repeats, his ass stinging from Karasuma's sudden slap.  
"Good." Karasuma slaps Nagisa again. "Begin."  
"One!" Nagisa cries.  
Slap!  
"Two!"  
Slap!"  
Three!  
By now, Nagisa has tears in his eyes and it's taking all his will power not to cum.  
Slap slap slap!  
"Six!"  
Two minutes later, sweating and panting, Nagisa's butt cheeks are sore and red and his enlarged penis is straining as he holds back his orgasm with all his might. He can feel Karasuma's erection underneath him against his stomach and it's becoming to much for him to bare.  
"Sensei, I need to cum!" he whines, blinking back his tears. "Please, please fuck me!"  
Without a word Karasuma adjusts the boy so that he is sitting on his cock. He guides it into the boy's gaping asshole and moves the boys hips so he is fully seated inside him.  
"Ah, yesss." Nagisa sighs as Karasuma's ginormous length enters him to the hilt. He starts to move his hips enjoying the feeling of Karasuma's penis as he rides his teacher.  
Karasuma angles himself so he is hitting Nagisa's prostate and Nagisa moans become louder as he grinds against his teacher.  
"Yes! Right there, yes!" Nagisa shouts as Karasuma rams into his prostate again and again.  
Karasuma wraps his hand around Nagisa and grabs hold of his penis again pumping in time to his thrusts. He squeezes it around the head to prevent Nagisa from cumming and Nagisa has tears running down his face again.  
Finally, Karasuma shoots his load into Nagisa and lets go of the boy's penis so he can release his load too.  
Once they are done, Karasuma pulls Nagisa off of him and sits up. "You made such a mess, Nagisa-kun. Look at that, my penis is dirty."  
"S-sorry," Nagisa turns around wiping tears off of his face. "I'll clean it up." He gets on his knees and begins to lick Karasuma clean.  
Karasuma can't help smiling again at the sight of Nagisa licking his penis and is glad for once that the camera is there to catch all of it. He starts to become hard again and without thinking, he grab a fistful of Nagisa's hair and shoves it into the boys mouth.  
Nagisa chokes and then eagerly begins sucking Karasuma off. When Karasuma cums again, Nagisa swallows his load with delight even though he has to lick Karasuma clean again.  
When Karasuma is finally clean, he buttons up his pants and begins the same administrations to Nagisa, bending down one one knee and licking his crotch, thighs, and ass clean. He then dresses the boy and closes the laptop.  
"Did I satisfy your curiosity?" Nagisa asks shyly.  
"Yes. You did quite well." Karasuma admits. "I see now why Koro-sensei and Irina-san like you so much."  
"Do you like me to, sensei?" Nagisa asks innocently, a mischievous smiling playing on his lips.  
Karasuma pretends to think about it for a moment before replying. "Think you can make time in your schedule for me again?"  
Nagisa beams. "Of course!"


	2. Nagisa's dream

**Summary for the Chapter:**

> Nagisa dreams of having sex with all three of his favorite teachers, Koro-sensei, Irina, and Karasuma at once. His dreams are a lot kinkier than he thought....

Nagisa watches the laptop screen sleepily as he lays in Irina's bed. On the screen three videos are playing at once. One of them is of Koro-sensei fucking Nagisa (who is dressed in skimpy maid's uniform), one is of Irina shoving a vibrator up his ass while giving him another one of her famous blow jobs, and the other is of his first time having sex with Karasuma in the faculty room. Irina is in the bathroom taking a shower and singing slightly off-key. The two of them just had another amazing BDSM session (Nagisa being the sub again) and it was currently just before midnight. Nagisa rubs his wrists, sore from his restraints, and sighs wistfully. If only he could have all his teachers at once. He rubs his tired eyes and closes the laptop, shoving it aside and drawing the silk bedsheets around him.  
"One day...one day I'll have all of them..." He murmurs before drifting off to sleep.  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
Nagisa wakes up to find him self bound all over with rope with his hands behind his back and hunched over on the floor with his faced pressed against the tiles and his butt waving in the air. In his ass is a vibrator set to full power as Irina stomps on his back with her high-heeled leather boots and cracks a whip. He's also wearing a collar attached to a chain which Irina holds the end of in her free hand. A necktie is wrapped around his penis as a makeshift cock ring and in his mouth is a gag.  
What in the world is going on!? Nagisa thinks to himself. Didn't Irina and I already do this!?  
He looks around and off to the side his sees the usual camera set up on a tripod. But behind the camera is none other than Koro-sensei filming the erotic scene and giggling.  
Koro-sensei is here!?  
Irina cracks the whip against Nagisa's butt cheeks and he moans around the gag as Irina switches the vibrator on again making his whole body shake with the power. Irina herself is wearing nothing more than fishnet stockings and a leather corset to match her boots.  
"Do you need to cum, Nagisa?" Irina croons, switching of the vibrator and digging her heel into his back.  
Nagisa nods against the floor and moans pleadingly. She whips him a few more times, laughing at the pathetic sight.  
"I think he's about to explode, Irina-san." Koro-sensei giggles again, angling he camera for the perfect shot.  
Irina smirks and kneels so she can unbind Nagisa's erection and at the same time switching the vibrator on again. Nagisa explodes immediately covering his chest and the floor with cum.  
"I'm surprised he lasted a whole 15 minutes." Irina strokes Nagisa's head. "Poor boy."  
"Let's get him on the bed." Karasuma is suddenly there wearing only his boxers. "I can't wait to fuck him."  
Karasuma too!? Nagisa is starting to believe that he's in heaven.  
Koro-sensei's tentacles wrap around the young boy and carry him over to a bed where he unceremoniously drops him on his back onto the mattress. Karasuma unties the rope around Nagisa only to tie it around just his wrists and ankles leaving him tied to the bed posts and spread out like a starfish.  
Irina comes over and removes the gag from his mouth to kiss him. "Reading for some loving?" She winks, and takes off her clothes.  
As she does this Koro-sensei starts to grope the boy with his many tentacles slithering around the Nagisa's body. He rubs the boys pink nipples making him shiver and teases his lower regions avoiding his penis for now. He slips one tentacles up Nagisa's ass and tickles his prostrate. Nagisa's pleasure filled moans fill the room and he arches his back, his penis becoming erect.  
Irina begins to suck and nibble at Nagisa's neck marking him with hickeys. Her large breasts are pressed against Nagisa's chest and playfully moves so she can shove them in his face.  
Once Nagisa's penis begins to drip with pre-cum, Karasuma wraps his hand around Nagisa's neglected length and begins to pump it.  
Nagisa's is crying now with joy. The stimulation from Irina kissing him, Koro-sensei hitting his prostate, and Karsuma feeling him up is making him go wild. They boy can hardly see straight or think clearly.   
"Irina...Koro...Kara-ah!"   
Karasuma's hand is suddenly replaced by Irina's mouth and she begins to kiss and lick his penis. Karasuma replaces her at his neck also leaving hickeys and then starts to suck on Nagisa's nipples.   
Irina licks up his length and lightly bites the head of his penis making Nagisa cry out. She then swallows it completely and moves up and down rapidly, deep throating him so hard he's beginning to see stars. Koro-sensei doubles the stimulation by wrapping a tentacle around his balls and squeezing them. He also spares another tentacle to wrap around Irina's boobs and fondles them.   
"I'm cumming!" Nagisa shrieks as he orgasms. Irina swallows his load with ease and pulls off his penis grinning. She wipes stray cum from her lips and then leans forward to kiss Nagisa again.   
Nagisa lays on the bed out of breath and begging for more. "Please don't let this be over yet..." he pants. He still hasn't been fucked by Koro-sensei or Karasuma yet. Koro-sensei pulls his tentacles out of Nagisa's ass and Irina undoes his restraints again. He then flips Nagisa onto his stomach and pulls him up so that his Nagisa is supporting himself with his arms and waving his ass is in the air. Karasuma crawls on the bed no longer wearing his boxers and sits in front of Nagisa cross-legged with his erection waving in his face. He pulls the boy's mouth to his cock and Nagisa takes it in his mouth eagerly.   
From behind, Koro-sensei slips his own cock into the boy's ass and begins to thrust into him without mercy. He know's Nagisa can take his speed by now. Nagisa's is moaning louder than ever before as he is fucked on both ends, his own penis swelling and flailing again against his chest and leaking. He grinds against Koro-sensei and deep throats Karasuma as Irina stands at the sides taking photos.   
Eventually, Irina takes the vibrator and presses it against Nagisa's balls. She turns it on and rubs it up and down his length.   
Nagisa sucks on Karasuma, Irina teases him, and Koro-sensei fucks him, pounding into the boy's ass like his life depends on it.   
Nagisa can hardly take it all anymore, yet he doesn't want it to end. This was the best moment of his life and a dream come true.   
"I'm cumming!" Koro-sensei and Karasuma shout at the same time and shoot their seed into the boy in his ass and down his throat respectively. Nagisa cums with them crying out around Karasuma's cock. Spit and cum dribble down his chin as he tries to swallow Karasuma's load. He pulls away with a trail of saliva and cum attached to his lip and Karasuma's cock.   
He collapses on the bed completely spent panting heavily. "Th-that was amazing!"   
Koro-sensei uses his speed to clean up Nagisa and the others and then goes to the camera to check out the footage.   
"I got such good photos too." Irina giggles, admiring her work. She's looking at the one she had taken just as Koro-sensei was slipping inside Nagisa and grins. "I bet if we posted these to a porn site you'd get a lot of fans."   
Nagisa can honestly care less at the moment if she decides to actually post them.   
"I don't want to wake up from this dream..." Nagisa yawns and promptly falls asleep.   
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
Nagisa wakes up to the sound of Irina watching getting dressed humming as she does so. He sits up groggily and glances at the clock. It's 11:15 am and way past break fast.   
"Good morning, Nagisa-kun~!" Irina winks at him as she clasps her bra. "Did you sleep well?"   
"I had the most amazing dream." Nagisa sighs. "You were in it."  
"I was?" Irina smiles. "What was it about?"   
"Koro-sensei and Karasuma were in it too. We all had sex together." Says Nagisa. "I wish I didn't have to wake up..."   
"Hmm~! Maybe one day it'll come true." Irina giggles. "Anyway, want to grab lunch somewhere?"   
"Sure! Can I take a shower first?" Nagisa asks. He had just realized that he had orgasmed in his sleep due to the dream.   
"Of course." Irina nods and Nagisa runs into the bathroom. Irina waits until she hears the shower running before she begins to laugh. "All four of us together? Not such a bad idea..."


End file.
